As a conventional opening/closing control device for a grille shutter, one described e.g. in PTL 1 is known. This grille shutter is for feeding ambient air for cooling, to a radiator disposed in an engine room of a vehicle. In this opening/closing control device, the temperature of water of the radiator is detected, and if the detected temperature of the water is higher than a predetermined temperature, the grille shutter is opened so as to cool the radiator, for the purpose of prevention of overheating of the engine. On the other hand, if the temperature of the water of the radiator is lower than the predetermined temperature, the grille shutter is closed, whereby an increase in air resistance due to opening of the grille shutter is avoided and fuel economy is improved.
Further, in the opening/closing control device, not only the temperature of the water of the radiator but also the operating state of an aircon (on/off of the aircon and position of a fan switch) and the temperature of the inside of the engine room are detected, and the opening/closing of the grille shutter is controlled according to detection results thereof.